weight gain?

I was cutting my weight down for about a year, went from 235- 166 at my lowest and I was only eating about 1000 calories a day, doing cardio and heavy weight lifting 4 days a week.  After reading some posts here I realized I needed to eat more because I am a 18 Year old male who is usually pretty active.  I increased my calories to about 1300-1500 calories per day and still do cardio and heavy weight lifting, but my weight has gone up to around 176 pounds and I believe it is on the rise, I'de like to think its all muscle but I am doubtful, can someone please explain to me why this is occuring?

Your body may take some time to adjust. Eating 1300-1500 plus working out is still not enough for your body. Give you weight flucutations 3 weeks before freaking out over it tho.

It may be muscle as well. You are the judge by your body size. Don't get too focused on what the scale is saying. Take note on how you feel and the size of your body. Muscle naturally weighs more than fat.

How long did it take with an increase of calories to gain the 10 pounds? A lot of factors can play into this. I'd continue to up your calories until you are at a healthy level. 

At 1400 calories, at 176 pounds, you are eating about 8 calories a pound.  A quadruplegic needs 10 calories a pound.  A sedentary older adult might need 11 to 12.  Young guys usually need 14 and up. It is just not possible that you are gaining fat on 8 calories a pound. You may have been previously dehydrated when you had that low weight. Or maybe you are using a digital... sometimes these go whacky.  So I would look for another explanation, or wait to see if it corrects. I agree you should eat at least 1500 calories.  You can safely eat 10 calories a pound without gaining weight... probably still lose on that amount. I am a 51-year-old woman, and maintain on 12 calories a pound... I would lose on 10 calories pound.

so what do you think is best? add on 400 calories starting tommorrow and start taking in around 1600 or waiting and gradually adding them on.  I also really have no idea where to get the calories from, where to add on more where to take of less etc.

You can't gain weight on 1,500 calories a day. What you're seeing is probably just some sort of weird water weight adjustment.

I realized I left a word out of my post. Digitial SCALES are sometimes whacky.

You should start eating 1500, then increase some each week... like 100 or 200 per day, per week. Watch the scale. If you  start gaining, you know it is time to level off.  I went from 1200 to 1300 a week, to 1400 for a while, realized I was still losing very slowly, so leveled off at 1500... I weigh 128. So surely you can eat 1500. 

alright thanks a lot

And I'm a 44 year old female and I eat 2300 calories a day (if I walk an hour a day) so you should be on way more.

Your body is probably retaining water and/or your scale is screwy. You can safely up your calories to your BMR level AT LEAST and I can guarantee you won't gain weight. So, like 1800. The additional activity will allow you to still lose weight as well.
Remember, your BMR is how many calories you body needs just to keep you alive!

Hmm.  Maybe you got taller.  You are 18.